1. Field of the Invention
This invention relates to cameras, and more particularly to the structure of assembly of flexible printed circuit boards within the camera housing.
2. Description of the Related Art
For the efficient utilization of the narrow space within the housing of the camera, particularly single lens reflex one, the wires of electrical circuitry were installed in the flexible printed circuit board. And, this board was only one in number, and took its place on the top face of the camera framework or aluminium die-cast body.
Recently, however, as the rate of using electronics and the number of capabilities are increased, the scale of necessary electrical circuits is increasing and the necessity of spreading many switchings and sensors over the various portions of the interior of the camera is encountered. Therefore, the printed circuit board must be extended from the top face of the framework to the side faces and even to the bottom.
For this case, if all the extended portions of the printed circuit boards are constructed in the unbroken form to that part of the board which lies on the top face of the framework, it is at the initial stage of assembling operation that the expanded printed circuit board of very large size is treated while its extensions are bent successively in conformance with the top, side and bottom faces of the framework. Such an installation has had a very low efficiency, giving large limitations on the assembly line and production cost.
To avoid this, the flexible printed circuit board may be divided into a plurality of corresponding parts to the top, sides and bottom of the framework, and, after these separate parts have been installed on the respective faces of the framework, any adjacent two of the parts are electrically connected with each other to establish a series of continuous wires over the entire electrical circuit system.
FIG. 13 shows an example of this conventional method. The flexible printed circuit board is divided into three separate parts, of which the first 1 is to be put on the top of the framework with its central part bent to conform with the roofs of the pentagonal prism, the second 2 is to be carried on the bottom, and the third 3 is to be positioned on the right hand side. Then, these parts 1, 2 and 3 are fixedly secured to the respective faces of the framework. Then, the first and third parts 1 and 3 are electrically connected to each other at their overlapped end portions 1a and 3a above the top face of the framework, and the second and third parts 2 and 3 are electrically connected to each other at their overlapped end portions 2a and 3a below the bottom of the framework. Thus, the flexible printed circuit board as a whole is regained in assembly on the framework.
This structure of construction of the multidivision flexible printed circuit board usually requires the use of at least two pairs of connectors, in the aforesaid example, 1a-and-3a and 2a-and-3b, of different wiring pattern at different places from each other. Moreover, regardless of whether solder or pressure sensitive electrically conductive rubber is in use, additional means must be provided for locating the ends of the two separate parts of the board in each pair in fixedly secured relation to the framework. Therefore, the problems of worsening the efficiency of the assembly line and producing no advantage on the cost are left unsolved. Another drawback of the aforesaid prior art is that an interconnection wire pattern that allows for the electrical circuits of the first and second separate parts of the printed circuit board to communicate with each other in some portions must be formed on the third part. This results in a decrease of the density of electrical circuits to be assigned to the third separate part of the printed circuit board.